Java多线程：join()方法的实际应用场景示例-蒲公英云

Java多线程：join()方法的实际应用场景示例

原创 Bertha 。 2024-12-13 18:54 99阅读 0赞

在Java多线程编程中，join()方法主要用于等待一个线程执行完毕。下面是一个实际应用场景的示例：

假设我们有一个ThreadA负责下载文件，而另一个ThreadB负责处理文件，比如解压、分析等。

class DownloadFile extends Thread {
    private String url;
    DownloadFile(String url) {
        this.url = url;
    }
    @Override
    public void run() {
        try {
            // 下载文件
            File downloadedFile = new File(url);
            // 如果下载成功，继续处理
            if (downloadedFile.exists()) {
                System.out.println("File downloaded successfully. Now processing...");
                // 这里可以添加ThreadB来处理下载后的文件
                ThreadB threadB = new ThreadB(downloadedFile);
                threadB.start();
            } else {
                System.out.println("Failed to download file.");
            }
        } catch (IOException e) {
            System.err.println("Error occurred while downloading file: " + e.getMessage());
        }
    }
}
class ProcessFile extends Thread {
    private File file;
    ProcessFile(File file) {
        this.file = file;
    }
    @Override
    public void run() {
        try {
            // 处理文件，这里以解压为例
            unzip(file);
            System.out.println("File processed successfully.");
        } catch (IOException e) {
            System.err.println("Error occurred while processing file: " + e.getMessage());
        }
    }
    private void unzip(File file) throws IOException {
        ZipInputStream zipIn = new ZipInputStream(new FileInputStream(file)));
        ZipEntry entry;
        // 解压一个文件，这里假设是"content.txt"
        while ((entry = zipIn.getNextEntry())) != null) {
            if (entry.getName().equals("content.txt"))) {
                File extractedContent = new File(entry.getName()).getAbsoluteFile());
                // 将解压出的文件内容复制到系统的临时目录
                FileInputStream fis = new FileInputStream(extractedContent));
                FileOutputStream fos = new FileOutputStream("/tmp/content.txt"));
                byte[] buffer = new byte[1024];
                while (fis.read(buffer) != -1) {
                    fos.write(buffer);
                }
                fis.close();
                fos.close();
                // 如果有处理文件的逻辑，这里可以添加
                System.out.println("Content of 'content.txt' successfully extracted and processed.");
            } else {
                System.out.println("Unsupported file during unzip process. Ignoring...");
            }
        }
        zipIn.closeEntry();
        zipIn.close();
    }
}